The problems occuring when determining such values will be described below by means of measured variables which are particularly important in the cigarette industry. These include the tear strength of paper, for example cigarette paper, filter paper or tipping paper, the filling capacity of cut tobacco, the hardness of smokeable articles, for example cigarettes, filters, filter rods, cigarettes and cigarillos, as well as the diameter and the circumference of smokeable articles.
Various measuring heads and evaluating devices which are sometimes very expensive and are capable of measuring only a single variable are needed for measuring these variables.
A combination measuring instrument for the filling capacity of cut tobacco and the hardness of cigarettes is described in an article from "Beitrage zur Tabakforschung", Volume 4, Edition 7, December 1968, pages 293 et seq. To determine the filling capacity of cut tobacco, the column height of a defined weight of tobacco is measured after a predetermined time under a specific load while, to determine the hardness of smokeable articles, in particular cigarettes, the change in diameter of cigarettes is determined after a predetermined period under a specific load. The instrument described in this article combines both possibilities, and the instrument can be converted by exchanging the measuring heads.
However, this combination instrument itself has the disadvantage that the filling capacity as well as the hardness can be measured only under precisely predetermined and defined parameters, namely under a specific load. A change in the load is permitted only by extra, expensive conversion of the instrument.